/**
 * Copyright 2018 The AMP HTML Authors. All Rights Reserved.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS-IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

/**
 * Stores indexed strings that are used in postMessage() calls from the worker.
 */
export class StringContext {
  private strings: Array<string>;

  constructor() {
    this.strings = [];
  }

  /**
   * Return a string for the specified index.
   * @param index string index to retrieve.
   * @return string in map for the index.
   */
  get(index: number): string {
    return this.strings[index] || '';
  }

  hasIndex(index: number) {
    return this.strings[index] !== undefined;
  }

  /**
   * Stores a string in mapping and returns the index of the location.
   * @param value string to store
   * @return location in map
   */
  store(value: string): void {
    this.strings.push(value);
  }

  /**
   * Stores a set of strings.
   * @param values
   */
  storeValues(values: Array<string>): void {
    values.forEach((v) => this.store(v));
  }
}
